Bills and coins represent only 3 percent of Sweden's economy, compared to an average of 9 percent in the eurozone and 7 percent in the U.S., according to the Bank for International Settlements, an umbrella organization for the world's central banks.

Forty-three percent (43%) of American adults have gone through a full week without paying for anything with cash or coins, according to a new Rasmussen Reports national telephone survey. Only slightly more (47%) have not done so.